Cable clamps

ABSTRACT

A cable clamp adapted for use in cable-stretching installations. The cable clamp includes stationary and swingable clamp assemblies where the swingable assembly is connected to the stationary assembly for swinging movement with respect thereto between clamping and unclamping positions. The stationary assembly is formed as a power cylinder for a piston guided for movement toward the swingable assembly and urging a lining which directly engages the cable toward a corresponding lining carried by the swingable assembly.

Grasman et a1.

1451 Set. 10, 1971 CABLE CLAMPS [75] Inventors: Rudolf Grasmaln; WalterHell;

Wilhelm Mullner, all of Vienna,

Austria [73] Assignee: Waagner-Biro A.G., Vienna, Austria [22] Filed:Sept. 15, 1972 [21] Appl. No.: 289,319

[30] ForeignApplication Priority Data Sept. 17, 1971 Austria 8119/71[52] Us. Cl. 24/132 WL, 24/249 DP, 24/263 DH, 269/31 [51] lint. Cl F16g11/00, A44h 21/00 1 Field -2,62 .49 PLZQEPL; 2.6 .125. 24/010. 26, 132ws, 132 HL, 132 R, 132

[56] References Cited UNITED STATES PATENTS 436,967 9/1890 Crawford.....24/249 DP 1,842,026 1/1932 Hulshizer 24/D1G. 26 2,615,682 10/1952 Stone81/57.l5 2,649,283 8/1953 Lundeen 81/57.19 2,695,189 11/1954 Chrisman24/263 DL 2,857,824 10/1958 Fair 24/263 DH 2,985,455 5/1961 Powell269/31 Primary Examiner-Bemard A. Gelak Attorney, Agent, orFirm-Steinberg and Blake [5 7 ABSTRACT A cable clamp adapted for use incable-stretching installations. The cable clamp includes stationary andswingable clamp assemblies where the swingable assembly is connected tothe stationary assembly for swinging movement with respect theretobetween clamping and unclamping positions. The stationary assembly isformed asja power cylinder for a piston guided for movement toward theswingable assembly and urging a lining which directly engages the cabletoward a corresponding lining carried by the swingable assembly.

6 Claims, 1 Drawing Figure BACKGROUND OF THE INVENTION the clamp whichcarries the 'hydraulicstructure is movable, difficulties are encounteredin connection with inserting the cable which is to be stretched intosuch a clamp.

SUMMARY OF THE INVENTION It is accordingly a primary object of thepresent invention to avoid these drawbacks.

In particular, it is an object of the invention to provide a cable clampstructure which is capable ofutilizing the force of a fluid underpressure while at the same time avoiding difficulties which areencountered when the fluid-pressure system is mounted on a movable partof the clamp. 1

According to the invention the clamp includes a stationary clamp meansand a swingable clamp means connected to the stationary clamp means forswinging movement with respect thereto between clamping and unclampingpositions. These stationary and swingable clamp means respectively havelinings for respectively engaging a cable at opposed positions of thelatter. The stationary clamp means has the form of a power cylinder andincludes a piston which is movable toward the swingable clamp means forurging the lining of the stationary clamp means toward the lining of theswingable clamp means.

BRIEF DESCRIPTION OF DRAWING The invention is illustrated by way ofexample in the accompanying drawing which forms part of this applicationand in which one embodiment of a clamp according to the invention isillustrated in a sectional elevation.

DESCRIPTION OF PREFERRED EMBODIMENTS Referring to the drawing, the cableclamp illustrated therein includes a lower stationary clamp means 1which has the form of a power cylinder 8 and which is pivotallyconnected with a swingable clamp means 2. The power cylinder 8 whichforms part of the stationary clamp means accommodates in its interior apiston 3 capable of pressing a lower clamp lining 4 of the stationaryclamp means 1 toward a clamp lining of the swingable clamp means 2. Forthis purpose the stationary clamp means 1 accommodates in its hollowinterior a guide member 9 which is slidably guided for movement towardand away from the lining 10 when a cable is clamped, this guide member 9being connected to the piston 3 to be moved thereby. The fluid underpressure which enters the power cylinder 8 may be a liquid in the caseof hydraulic operation or compressed air in the case of pneumaticoperation.

The upper clamp lining 10 is directly carried by the swingable clampmeans 2 which is swingable on a pin 11 carried by the stationary clampmeans 1.

A fluid-pressure means is provided to swing the clamp means 2 withrespect to the pin 11. This fluidpressure means includes apower-cylinder 7 swingably connected by the pin 12 to the stationaryclamp means 1 and a piston shiftable in the cylinder 7 and having apiston rod pivotally connected by a pin 13 to the swingable clamp means2.

A releasable lock means 5 is provided for releasably locking theswingable clamp means 2 in the illustrated position when a cable isclamped. This releasable locking means includes the lock lever 5 whichisswingable .on a pin 14 carried by the stationary clamp means 1. A

fluid-pressure means 6 has a power cylinder pivotally connected at oneend to the stationary clamp means 1, this cylinder accommodating apiston whose piston rod is pivotally connected to the lock lever 5 onthe side of pin 14 opposite from the locking projection at the top ofthe lever 5 which overlaps the left hand portion of the swingable clampmeans 2, as viewed in the drawing, to maintain the clamp means 2 in itslocked operating position.

In order to bring about clamping of a cable, the piston 3 is constructedas a double-acting piston and has lower and'upper chambers separated bya flange 17 and respectively communicating with the bores 15 and 16through which a pressure fluid such as oil or air is adapted to beintroduced. When fluid under pressure is introduced through the bore 15,the chamber above flange 17 may be vented through the bore 16 and thelining 4 will be pressed toward the lining 10. When fluid under pressureis introduced through the bore 16 the chamber beneath flange 17 isvented through the bore 15 so that the piston 3 will be retracted. Theguide piece 9 is fixed to the piston 3 by way of a bolt 18.

In cable-stretching systems, several cable clamps are disposed onebehind the other'with their upper and lower portions acting as mutualsupports for each other and with the last clamp in the series beingsupported against a frame of the installation. To simplify theillustration the cells of the pressure-transmitting components are notillustrated.

For safety purposes, it is not possible to introduce fluid underpressure into the chamber beneath the flange 17 unless the releasablelock means 5 has first been moved to its locking position shown in thedrawing. Of course, the swingable clamp means 2 is first moved to theposition shown in the drawing before the lock means is displaced to theposition shown in the drawing. It is only then that it is possible withthe safety device to urge the piston 3 toward the lining 10.

As is apparent from the drawing, when the swingable clamp means 2 is inits clamping position shown in the drawing, the lining 10 of theswingable clamp means and the lining 4 of the stationary clamp meansrespectively have inner concave surfaces opposed to each other and eachextending approximately around a given axis which is perpendicular tothe axis of the power cylinder 8. Also, as is apparent from the drawing,the stationary clamp means 1 has a pair of opposed walls part of whichform part of the power cylinder 8, with these opposed walls extendingparallel to the axis of the cylinder 8. In its clamping position theswingable clamp means 2 has opposed portions which are respectively inline with the opposed walls of the stationary clamp means 1, theseopposedwalls being shown at the left and right in the drawing. It willbe noted that the lock means 5 engages the left portion of the swingableclamp means 2 which is in line with the left wall of the stationaryclamp means while the pivot means 11 is operatively connected with theright portion of the swingable clamp means 2 which is in line with theright wall of the stationary clamp means 1, as viewed in the drawingi Asa result, since these opposed walls of the stationary clamp means 1 aresituated equidistantly from the axis of the power cylinder 8 the forceapplied to the piston 3 is substantially evenly distributed between theopposed walls inasmuch as the moment arms are substantially equal, andin addition these moment arms are necessarily extremely short, becausethe opposed left and right portions of the swingable clamp means 2 arerespectively in line with the opposed walls of the stationary clampmeans 1, when the swingable clamp means 2 is in its illustrated clampingposition, and as a result it is possible for the structure of theinvention to withstand extremely large forces as are required forpurposessuch as cable stretching.

What is claimed is:

1. In a clamp for clamping a cable or the like during a stretchingoperation such as a cable-stretching operation, stationary clamp meanshaving a lining adapted to engage a cable or the like, swingable clampmeans swingably connected to said stationary clamp means for movement toa clamping position and having a lining adapted to engage a cable or thelike at a part thereof diametrically opposed to the lining of saidstationary clamp means, said linings respectively having inner concavesurfaces each extending approximately 180 around a given axis when saidswingable clamp means is in said clamping position thereof, saidstationary clamp means having in part the construction of a powercylinder and including a pair of opposed walls forming part of saidcylinder and extending parallel to and situated at equal distances onopposite sides of the axis of said cylinder, said cylinder axis beingperpendicular to said given axis, and said stationary clamp meansaccommodating in said cylinder a slidable piston which is operativelyconnected with said lining of said stationary clamp means for urging thelatter lining along the axis of said cylinder toward the lining of saidswingable clamp means when said swingable clamp means is in saidclamping position and fluid under pressure is introduced into saidcylinder of said stationary clamp means, said swingable clamp meanshaving when in said clamping position thereof a pair of opposed portionswhich are respectively in line with said opposed walls of saidstationary clamp means, lock means operatively connected with saidstationary clamp means and engaging one of said opposed portions of saidswingable clamp means for releasably locking said swingable clamp meansin said clamping position thereof with respcct to said stationary clampmeans, and pivot means swingably connecting the other of said opposedportions of said swingable clamp means, which is in line with the otherof said opposed walls of said stationary clamp means, to said stationaryclamp means for swingable movement with respect thereto about an axiswhich is parallel to said given axis.

2. The combination of claim 1 and wherein said piston is a double-actingpiston.

3. The combination of claim 1 and wherein a fluid pressure means isoperatively connected with said stationary and swingable clamp means forswinging said swingable clamp means with respect to said stationaryclamp means.

4. The combination of claim 1 and fluid-pressure means operativelyconnected with said lock means and said stationary clamp means fordisplacing said locking means between locking and unlocking positions.

5. The combination of claim 1 and safety means preventing operation ofsaid piston unless said swingable lock means is locked with respect tosaid stationary lock means.

6. The combination of claim 1 and wherein said stationary clamp meansincludes a guide member carrying said lining of said stationary clampmeans and guided by said opposed walls of said stationary clamp meansfor movement toward and away from said lining of said swingable clampmeans, when said swingable clamp means is in said clamping positionthereof, said piston being operatively connected to said guide memberfor moving the latter.

1. In a clamp for clamping a cable or the like during a stretchingoperation such as a cable-stretching operation, stationary clamp meanshaving a lining adapted to engage a cable or the like, swingable clampmeans swingably connected to said stationary clamp means for movement toa clamping position and having a lining adapted to engage a cable or thelike at a part thereof diametrically opposed to the lining of saidstationary clamp means, said linings respectively having inner concavesurfaces each extending approximately 180* around a given axis when saidswingable clamp means is in said clamping position thereof, saidstationary clamp means having in part the construction of a powercylinder and including a pair of opposed walls forming part of saidcylinder and extending parallel to and situated at equal distances onopposite sides of the axis of said cylinder, said cylinder axis beingperpendicular to said given axis, and said stationary clamp meansaccommodating in said cylinder a slidable piston which is operativelyconnected with said lining of said stationary clamp means for urging thelatter lining along the axis of said cylinder toward the lining of saidswingable clamp means when said swingable clamp means is in saidclamping position and fluid under pressure is introduced into saidcylinder of said stationary clamp means, said swingable clamp meanshaving when in said clamping position thereof a pair of opposed portionswhich are respectively in line with said opposed walls of saidstationary clamp means, lock means operatively connected with saidstationary clamp means and engaging one of said opposed portions of saidswingable clamp means for releasably locking said swingable clamp meansin said clamping position thereof with respect to said stationary clampmeans, and pivot means swingably connecting the other of said opposedportions of said swingable clamp means, which is in line with the otherof said opposed walls of said stationary clamp means, to said stationaryclamp means for swingable movement with respect thereto about an axiswhich is parallel to said given axis.
 2. The combination of claim 1 andwherein said piston is a double-acting piston.
 3. The combination ofclaim 1 and wherein a fluid pressure means is operatively connected withsaid stationary and swingable clamp means for swinging said swingableclamp means with respect to said stationary clamp means.
 4. Thecombination of claim 1 and fluid-pressure means operatively connectedwith said lock means and said stationary clamp means for displacing saidlocking means between locking and unlocking positions.
 5. Thecombination of claim 1 and safety means preventing operation of saidpiston unless said swingable lock means is locked with respect to saidstationary lock means.
 6. The combination of claim 1 and wherein saidstationary clamp means includes a guide member carrying said lining ofsaid stationary clamp means and guided by said opposed walls of saidstationary clamp means for movement toward and away from said lining ofsaid swingable clamp means, when said swingable clamp means is in saidclamping position thereof, said piston being operatively connected tosaid guide member for moving the latter.